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<h1>Thulium, Tm</h1>

Thulium (Tm) is a rare-earth metal, belonging to the lanthanide series of the periodic table. It is silvery-white and soft, displaying properties common to most of the rare-earth elements. Thulium can be isolated from other rare earths through ion-exchange reactions. While thulium is not as abundant or widely used as other rare earths, it has several niche applications. One of its artificially-produced isotopes, Tm-170, is employed as a radiation source in portable X-ray devices. Additionally, thulium lasers, specifically Tm:YAG lasers, have applications in medical procedures, industrial drilling, and research.

<h2>External links</h2>
<ul>
<li><a href="https://en.wikipedia.org/wiki/Thulium">Thulium - Wikipedia</a></li>
<li><a href="https://www.webelements.com/thulium/">Thulium - WebElements</a></li>
<li><a href="http://periodic.lanl.gov/69.shtml">Thulium - Periodic table of elements: Los Alamos National Laboratory</a></li>
</ul>
